The best way to relieve yourself of guilt is to re-live it.
Sit in a meditative mood.
Close your eyes and one by one bring to surface each of your guilts.
Re-live the wounds completely.
Do not console yourself about the guilt.
Open your eyes and write it all down in detail.
Write in as detailed a way as possible.
You will see that you are free from all the guilt feelings that you are carrying.
Reference:
Source:
https://gov.shrikailasa.org/livingenlightenment/ (Download the free e-book in your language)